Human Anatomy

1. © 2012 Pearson Education, Inc.
24
The Respiratory
System
PowerPoint®
Lecture Presentations prepared by
Steven Bassett
Southeast Community College
Lincoln, Nebraska

2. © 2012 Pearson Education, Inc.
Introduction
Cells obtain oxygen and eliminate
carbon dioxide.
 The respiratory system facilitates the
exchange of gases between the air and
the blood.
 Blood carries oxygen to peripheral
tissues.
 Blood accepts the carbon dioxide from
peripheral tissues.

3. © 2012 Pearson Education, Inc.
An Overview of the Respiratory System
•The upper respiratory system
•Consists of:
•Nose, nasal cavity, sinuses, and pharynx
•The lower respiratory system
•Consists of:
•Larynx, trachea, bronchi, bronchioles, and alveoli

4. © 2012 Pearson Education, Inc.
Figure 24.1 Structures of the Respiratory System
Nasal cavity
Sphenoidal sinus
Internal nares
Nasopharynx
Esophagus
Clavicle
Ribs Diaphragm
Bronchioles
Bronchus
Trachea
Larynx
Nose
Nasal conchae
Frontal sinus
Tongue
Hyoid bone
RIGHT
LUNG
LEFT
LUNG
UPPER
RESPIRATORY
SYSTEM
LOWER
RESPIRATORY
SYSTEM

5. © 2012 Pearson Education, Inc.
An Overview of the Respiratory System
Functions of the Respiratory System
 Providing an area for gas exchange
 Moving air to and from the exchange surface
 Protecting respiratory surfaces
 Defending the respiratory system and other tissues
from invasion by pathogenic microorganisms
 Producing sounds involved in speaking, singing, or
nonverbal communication
 Assisting in the regulation of blood volume, blood
pressure, and the control of body fluid pH
 Difficult or labored breathing is called dyspnea.

6. © 2012 Pearson Education, Inc.
An Overview of the Respiratory System
The Respiratory System
 Includes the nose, nasal cavity and sinuses,
pharynx, larynx, trachea, and conducting
passageways
 The respiratory tract consists of the following:
 Conduction portion
 Respiratory portion
 The respiratory bronchiles
 The alveoli

7. © 2012 Pearson Education, Inc.
The Upper Respiratory System
Structures in the head are part of the upper respiratory system.
 Nose
 The outer opening of the nose is called external nares.
 Nose is the main organ to filter, warm and humidify the air.
 Nasal cavity
 Paranasal sinuses
 Nasal septum is made of ethmoid and vomer bones.
 the separation between nasal and oral cavity is provided by:
 Soft palate
 Uvula: seals the opening between oral cavity and nasopharynx.
 Hard palate
 Palatine process of maxilla
 Palatine bone
 Pharynx
 the common pathway of food and air.
 Has three sections: nasopharynx (contains auditory tube),
oropharynx, laryngopharynx.

8. © 2012 Pearson Education, Inc.
Figure 24.4a Respiratory Structures in the Head and Neck, Part II
A sagittal section of the head and neck
Nasal cavity
Internal nares
Nasopharynx
Pharyngeal tonsil
Entrance to auditory tube
Soft palate
Palatine tonsil
Oropharynx
Epiglottis
Aryepiglottic
fold
Laryngopharynx
Glottis
Vocal fold
Esophagus
Frontal sinus
Superior
Middle
Inferior
Nasal
conchae
Nasal vestibule
External nares
Hard palate
Oral cavity
Tongue
Mandible
Lingual tonsil
Hyoid bone
Thyroid gland
Trachea
Cricoid cartilage
Thyroid cartilage

9. © 2012 Pearson Education, Inc.
The Lower Respiratory System
Structures in the neck and thoracic cavity
are parts of the lower respiratory system
 Larynx
 Trachea
 Bronchi
 Bronchioles
 Alveoli

10. © 2012 Pearson Education, Inc.
Figure 24.6a Anatomy of the Larynx
Anterior view of the intact larynx
Trachea
Larynx
Cricoid cartilage
Thyroid
cartilage
Tracheal cartilages
Cricotracheal ligament
(extrinsic)
Cricothyroid ligament
(intrinsic)
Laryngeal
prominence
Thyrohyoid ligament
(extrinsic)
Hyoid bone
Lesser cornu
Epiglottis

11. © 2012 Pearson Education, Inc.
Figure 24.6b Anatomy of the Larynx
Posterior view of the intact
larynx
Tracheal cartilages
Epiglottis
Cricoid
cartilage
Thyroid
cartilage
Vestibular
ligament
Vocal
ligament
Arytenoid cartilage

12. © 2012 Pearson Education, Inc.
Figure 24.7ab The Vocal Cords
Glottis in the open
position
Glottis in the closed
position
ANTERIOR
POSTERIOR
Aryepiglottic
fold
Glottis (open)
Corniculate
cartilage
Cuneiform
cartilage
Vestibular
fold
Vocal fold
Epiglottis
Root of tongue
Corniculate cartilage
Glottis (closed)
Vocal fold
Vestibular fold
Epiglottis

13. © 2012 Pearson Education, Inc.
Figure 24.7bc The Vocal Cords
Glottis in the closed
position
This photograph is a representative
laryngoscopic view. For this view the
camera is positioned within the
oropharynx, just superior to the larynx.
ANTERIOR
POSTERIOR
Corniculate cartilage
Glottis (closed)
Glottis (open)
Vocal fold
Vestibular fold
Epiglottis
ANTERIOR
POSTERIOR
Cuneiform cartilage
in aryepiglottic fold
Root of tongue

14. © 2012 Pearson Education, Inc.
Figure 24.8 Movements of the Larynx during Swallowing
Tongue forces
compacted bolus
into oropharynx.
Laryngeal movement
folds epiglottis;
pharyngeal muscles
push bolus into
esophagus.
Bolus moves along
esophagus; larynx
returns to normal
position.
Hard palate
Soft palate
Tongue
Bolus
Epiglottis
Larynx
Trachea
Soft palate
Bolus
Epiglottis
Bolus
Epiglottis
Trachea

15. © 2012 Pearson Education, Inc.
The Trachea
Also called the windpipe
 Walls contain cartilage rings
 Enters thoracic cavity anterior to
esophagus
 Bifurcates at the carina

16. © 2012 Pearson Education, Inc.
Figure 24.9a Anatomy of the Trachea and Primary Bronchi
Anterior view showing the plane of section for part (b)
Larynx
Trachea
Hyoid
bone
Annular
ligaments
Tracheal
cartilages
Location of carina
(internal ridge)
Root of
left lung
Root of
right lung
Superior
lobar bronchus
Lung
tissue
Middle lobar
bronchus
Primary
bronchi
Secondary
bronchi
Inferior
lobar bronchi
Superior
lobar bronchus
RIGHT LUNG LEFT LUNG

17. © 2012 Pearson Education, Inc.
The Primary Bronchi
 Wall structure similar to tracheal wall
 One per lung
The right primary bronchus supplies the right lung, and the
left supplies the left lung.
Right bronchus has three branches and left one has
two.
The middle lobar bronchus is only found in the right
lung.
Right has a larger diameter, descends toward lung at
steeper angle, less resistant to air flow and wider; easier for
foreign objects to get lodged there

18. © 2012 Pearson Education, Inc.
Figure 24.11 Bronchi and Bronchioles
Primary bronchus
Cartilage ring
Root of lung
Secondary (inferior
lobar) bronchus
Cartilage plates
Visceral pleura
Respiratory
epithelium
Smooth muscle
BRONCHIOLE
Lobule Respiratory
bronchioles
Terminal
bronchiole
Bronchioles
Tertiary
bronchi
Secondary
(superior lobar)
bronchus
LEFT LUNG

19. © 2012 Pearson Education, Inc.
The Lungs
Lungs are divided into lobes:
 3 lobes on right: superior, middle, and inferior
 2 lobes on left: superior and inferior
 Left lung contains cardiac impression and cardiac
notch.
 Fissures divide the lungs into lobes.
 Bronchi branch out into smaller
bronchioles.
 Bronchioles lead to alveoli.

20. © 2012 Pearson Education, Inc.
Figure 24.10ab Superficial Anatomy of the Lungs
Anterior view of the opened chest,
showing the relative positions of
the left and right lungs and heart.
Diagrammatic views of
the lateral surfaces of
the isolated right and
left lungs
Superior lobe
RIGHT LUNG
Horizontal fissure
Middle lobe
Oblique fissure
Inferior lobe
Liver,
right lobe
Liver,
left lobe
Boundary between
right and left
pleural cavities
LEFT LUNG
Superior lobe
Oblique fissure
Fibrous layer
of pericardium
Inferior lobe
Falciform ligament
Cut edge of
diaphragm
Apex Apex
Horizontal
fissure
Oblique
fissure
Base
RIGHT LUNG LEFT LUNG
Superior
lobe
Middle
lobe
Inferior
lobe
Inferior
lobe
Superior lobe
Cardiac
notch
Oblique
fissure
Base
Lateral Surfaces

21. © 2012 Pearson Education, Inc.
Figure 24.10c Superficial Anatomy of the Lungs
Diagrammatic views of
the medial surfaces of
the isolated right and
left lungs
RIGHT LUNG LEFT LUNG
Inferior
lobe
Inferior
lobe
Superior
lobe
Superior
lobe
Middle
lobe
Cardiac
impression
Pulmonary
veins
Horizontal
fissure
Oblique
fissure
Groove for
esophagus
Apex
Superior lobar bronchus
Pulmonary arteries
Middle lobar bronchus
Superior lobar bronchus
Inferior lobar bronchus
Hilum
Base
Groove
for aorta
Pulmonary
veins
Oblique
fissure
Diaphragmatic
surface
Medial Surfaces

22. © 2012 Pearson Education, Inc.
Figure 24.13a Bronchi and Bronchioles
The structure of one portion of a single pulmonary lobule
Bronchopulmonary
segment
Alveoli in a
pulmonary
lobule
Smaller
bronchi
Tertiary
bronchi
Secondary
bronchus
Visceral
pleura
Left
primary
bronchus
Trachea
Bronchioles
Terminal bronchiole
Respiratory bronchiole
Branch of
pulmonary
vein
Capillary
beds
Elastic fibers
Respiratory
bronchiole
Terminal
bronchiole
Bronchial artery (red),
vein (blue), and
nerve (yellow)
Bronchiole
Respiratory
epithelium Branch of
pulmonary
artery
Smooth muscle
around terminal
bronchiole
Arteriole
Alveolar
duct
Lymphatic
vessel
Alveoli
Alveolar sac
Interlobular
septum
Visceral pleura
Pleural cavity
Parietal pleura

23. © 2012 Pearson Education, Inc.
The Lungs
• Epithelium of the lung includes:
– Simple squamous epithelium, type I cell, which
are respiratory epithelium.
– Septal cells, type II, which produces
surfactant. Surfactant reduces the surface
tension in the fluid coating alveolar surfaces.
– Roaming macrophages.

24. © 2012 Pearson Education, Inc.
Figure 24.14cd Alveolar Organization
Diagrammatic sectional view of alveolar structure
and the respiratory membrane
Pneumocyte
type I cell
Alveolar
macrophage
Endothelial
cell of
capillary
Alveolar
macrophage
Pneumocyte
type II cell
Elastic
fibers
Capillary
The respiratory membrane
Alveolar air space
Capillary lumen
Red blood cell
Nucleus of
endothelial
cell
Endothelium
SurfactantAlveolar
epithelium
Fused
basal
laminae
0.5 µ m

25. © 2012 Pearson Education, Inc.
The Pleural Cavities and Pleural Membranes
 Parietal pleura lines the pleural cavity.
 Visceral pleura covers the lungs.
 Pleural fluid causes membranes to stick
together but still slide on one another.

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Figure 24.15 Anatomical Relationships in the Thoracic Cavity
Left lung,
inferior lobe
Posterior
mediastinum
Bronchi
Parietal pleura
Left pleural cavity
Visceral pleura
Left lung,
superior lobe
Body of sternum
Ventricles
Rib
Pericardial
cavity
Right lung,
middle lobe
Right pleural
cavity
Right lung,
inferior lobe
Oblique fissure
Atria
Esophagus
Aorta
Spinal cord

27. © 2012 Pearson Education, Inc.
Respiratory Muscles and Pulmonary Ventilation
 Inspiratory muscles
 Diaphragm
 External intercostal muscles
 Expiratory muscles
 Usually not needed due to elastic recoil of lungs and thoracic
cavity
 Accessory respiratory muscles
 Inspiration
 Sternocleidomastoid, serratus anterior, pectoralis minor, and
scalene muscles
 Expiration
 Transversus thoracis, oblique, and rectus abdominis muscles
 Internal intercostal muscles

28. © 2012 Pearson Education, Inc.
Figure 24.16b Respiratory Muscles
The primary and accessory
muscles of respiration
Sternocleidomastoid
muscle
Scalene muscles
Pectoralis
minor muscle
Serratus
anterior muscle
Accessory Muscles
of Inspiration
Diaphragm
Accessory Muscles
of Exhalation
External intercostal muscles
Internal intercostal
muscles
Transversus thoracis
muscle
External oblique
muscle
Internal oblique
muscle
Rectus abdominus

29. © 2012 Pearson Education, Inc.
Figure 24.16c Respiratory Muscles
Inhalation, showing the primary and accessory respiratory
muscles that elevate the ribs and flatten the diaphragm.
Diaphragm
Sternocleidomastoid
muscle
Scalene
muscles
Pectoralis
minor muscle
Serratus
anterior muscle
External
intercostal
muscles

30. © 2012 Pearson Education, Inc.
Figure 24.16d Respiratory Muscles
Exhalation, showing the primary and accessory respiratory
muscles that depress the ribs and elevate the diaphragm.
Transversus
thoracis muscle
Internal intercostal
muscles
Rectus abdominis
and other abdominal
muscles (not shown)

31. © 2012 Pearson Education, Inc.
Figure 24.17 Respiratory Centers and Reflex Controls
KEY
= Stimulation
= Inhibition
Phrenic nerve
Motor neurons
controlling other
respiratory muscles
Dorsal
respiratory
group (DRG)
Ventral
respiratory
group (VRG)
Respiratory
rhythmicity
centers
Motor neurons
controlling
diaphragm
Spinal
cord
Stretch
receptors
of lungs
Diaphragm
Chemoreceptors and
baroreceptors of carotid
and aortic sinuses
N X
N IX and N X
Pneumotaxic
center
Apneustic
center
Medulla
oblongata
CSF
CHEMORECEPTORS
Pons
Cerebrum
HIGHER CENTERS
Cerebral cortex
Limbic system
Hypothalamus

32. © 2012 Pearson Education, Inc.
Aging and the Respiratory System
Elastic tissue deteriorates, reducing the lungs’
ability to inflate and deflate.
 Movements of the rib cage are restricted by
arthritic changes.
 Some degree of emphysema is normally
found in individuals age 50–70.